Theories & Research

There are numerous theories regarding the etiology of HG;
however, none are,
as of yet, conclusive. A cause is very difficult to determine
and is most
likely not due to only one factor. It may vary between women
depending on
biological make-up (genetics), body chemistry, and overall
health. However,
as is common in poorly understood disorders, a psychological
cause is named when a physiological one is not known.

This
is especially true when so many of the symptoms like nausea
are not objectively measurable. Thus it is easy to dismiss
a woman's symptoms as being psychological, exaggerated,
or
imaginary, when in fact they are very real and may in fact
be very severe. However, accurately determining severity
is
difficult, especially if there is not obvious "proof" of
how sick a woman is. Proof, such as severe weight loss or
dehydration,
often comes after she is very sick for some time, and it
is then more difficult to manage her symptoms.

Early Research & Perspectives

Hyperemesis gravidarum became a recognized disorder several
centuries ago, but the first research appears to have been
published in the 18th century. Incidence in the United States
is reported to be about 60,000 cases annually; however, that
number only reflects those treated as inpatients, not those
treated at home or in outpatient/urgent care facilities.
With the focus on cost reduction in health care, the majority
of women are not admitted to the hospital. Thus the incidence
of HG is likely several times greater than suggested. It
is not actually a rare disorder. If it is not treated, a
mother can suffer greatly and may even have acute or chronic
anxiety and/or depression from the trauma of incessant nausea
and vomiting.

HG was first thought to be related to a physiological
cause such as toxins, ulcerations, or infection in a related
organ. A physical cause such as abnormalities of the
female reproductive
system was also suggested. Early in the 20th century,
a psychological cause was proposed by those subscribing
to psychoanalytic
theories. Unfortunately, despite the lack of evidence
in these biased studies, their assumptions have persisted
to this day. Every type of medical professional from
pharmacist
to nurse and allopathic to naturopathic physician is
typically
taught that HG is a psychological disorder. Many textbooks
and published medical research still erroneously suggest
that HG is psychosomatic, as well. It is no surprise
that women suffering from HG are often left untreated or
not
taken seriously. This belief has been passed from generation
to
generation of health professional despite the multitude
of evidence showing many contributing factors unrelated
to psychological
conflicts.

Currently, many theories are being tested, and new ones
emerge every year. Most center around known pregnancy-related
factors
like hormonal changes (e.g. estrogen increase) and
physical changes (e.g. relaxed esophageal sphincter) since
the
onset is related to pregnancy and ends before or at
delivery. Research is limited and minimal funding is granted
for
hyperemesis
research, so high-quality studies with decisive results
are uncommon.